Preheat oven to 450 degrees. Line a baking sheet with parchment paper.

1. Sift 2 ½ cups of flour, baking powder, and salt together in a spacious mixing bowl.

2. Place the yams, brown sugar, ginger, cinnamon, nutmeg and milk in the bowl of a food processor or electric mixer and mix until smooth. Set aside.

3. Cut the butter into small pieces and add it to the flour mixture using a pastry blender or fork. Work the mixture until it forms a coarse meal of small, buttery kernels.

4. Fold in the yam mixture and stir to form a soft dough. Add extra flour if it’s too sticky, but avoid overworking the dough.

5. Transfer the dough to a clean, floured surface and roll it out to 1/2-inch thickness.

6. Cut out biscuits using a 2 ½-inch round cutter. Place them on the baking sheet and bake for 18 to 20 minutes, until cooked through.

7. Remove from the oven and immediately brush with butter.

8. Let cool on the baking sheet for 10 minutes, then transfer to a cooling rack.